JP5066086B2 - Exterior voice coil assembly for use in loud loudspeaker applications - Google Patents

Description

  This application claims the priority and benefit of US Provisional Patent Application No. 60 / 703,009, filed July 28, 2005, in accordance with US Patent Law. It is assumed that the contents disclosed in this patent application are included in this specification by touching this patent application.

  The present invention relates to an electromechanical loudspeaker motor structure, and more particularly, to an exterior voice coil assembly for use in loudspeaker and long excursion loudspeaker applications, and a method for manufacturing an exterior voice coil assembly. About.

  In recent years, the loudspeakers (for example, low-frequency drivers or woofers) that produce large volumes and large displacements are emphasized in the market in recent years, and manufacturers can withstand the level of abuse that has never been imagined before. Trying to manufacture. DB drag racing and other forms of loudness level competition have created amplifiers and loudspeakers that dissipate several kW over time. Such products have been incorporated into automated acoustic systems that generate an acoustic output in excess of 170 db before failure.

  The limitations of loudspeakers are well understood. Specifically, the high power signal drives the loudspeaker diaphragm or cone to greatly displace it, thereby avoiding the movement of the diaphragm, which is normally reciprocating, when driven by a relatively challenging acoustic signal. Cause alignment. A typical prior art woofer uses a circular basket that supports a frustoconical driver diaphragm. The diaphragm has a circular periphery that supports an annular surround or suspension. In general, the small circular end of the frustoconical diaphragm supports a substantially cylindrical voice coil former. A conductive voice coil having a positive end terminal and a negative end terminal is wound around the winding mold.

  Conventional woofers use a support basket that closely follows the frustoconical shape of the driver diaphragm and supports the motor magnet and the circular diaphragm surround in a coaxially aligned manner, which allows the diaphragm to be It can move in the axial direction in response to electrical excitation.

  Failure of loudspeakers and woofers is often caused by thermal or mechanical overload problems. In order to provide a competitive sound pressure level, it is necessary to provide a large amount of power, and a signal with such power requires a very large current to flow through the voice coil conductor, and thus a large amount of power. The woofer diaphragm is displaced greatly. Thus, when the displacement is very large, a very large mechanical load is generated on the diaphragm and its supporting suspension. In competition, the operator tries to play as loud as possible, often overdriving the loudspeaker drive, burning out the voice coil or opening the circuit. Such extreme use can mechanically damage the cone, surround, and “spider” suspension members, or, during movement, misaligned coils rub the annular gap edges of the motor, causing voice coils May be damaged.

  Accordingly, there is a need for a voice coil that can withstand the rigors of the latest high volume, large displacement loudspeaker applications.

  When assembling a loudspeaker, typically one important alignment process greatly increases the cost and time of the assembly operation. The loudspeaker motor must be assembled with a substantially cylindrical voice coil positioned precisely and concentrically within the annular motor gap. The cone and voice coil are usually part of the first assembly, which is lowered into a second assembly that includes a motor and a basket. If the assembler misaligns the voice coil within the annular magnetic gap, the voice coil will contact or rub against the cylindrical shape of the magnetic gap, thereby causing deformation or breakage of the loudspeaker. The importance of this alignment increases the loudspeaker assembly costs.

  Accordingly, there is a need for a voice coil assembly that can reduce the importance and cost of the loudspeaker assembly process.

  Accordingly, the present invention solves the above-mentioned problems in at least two ways. In a first method, the present invention provides a voice coil assembly with a protective or armor that is designed to withstand the use of loud loudspeakers with high displacement. Second, the present invention provides an exterior voice coil assembly that can reduce the importance and cost of the loudspeaker assembly process. Improved features may be achieved individually or in combination and the invention should not be construed as requiring the combination of two or more of these advantages.

  In the first embodiment, the outer voice coil assembly of the present invention includes a porous substrate in which a winding mold is substantially impregnated with a curable resin, that is, saturated. After the conducting coil is wound or arranged on the outer surface or the inner surface of the winding mold, it is enclosed in a stiffening body wound around the conducting coil. For loudspeaker applications, the lead coil is known as a voice coil. The stiffener is preferably a porous substrate substantially impregnated or saturated with a curable resin. The outer encapsulated stiffener is also called an exterior layer. Preferably, this process effectively encapsulates the wire coil in inner and outer layers made of fabric and resin. The former and the stiffener are preferably coextensive and have the same cylindrical length along their common axis. After the finished outer voice coil assembly is cured to a selected shape, the side walls of the outer voice coil assembly are preferably configured to allow ventilation, i.e., fluid communication, between the interior and exterior of the outer voice coil assembly. A plurality of through holes that are spaced apart from each other are formed by drilling.

  The lead coil has first and second coil ends, which are preferably flat ribbon-like shapes that can be snugly attached to the side walls of the mould, emanating from the proximal end of the outer voice coil assembly. Soldered to the conductor end. As a result, the exterior or stiffener protects the connecting conductor of the coil from the side.

  In a preferred embodiment, the armored voice coil assembly is advantageously provided with structural integrity and rigidity by at least two substantially coaxial cylindrical walls. Each of the cylindrical walls is relatively thin and is therefore a good heat transfer body when compared to conventional relatively thick voice coil formers.

  The manufacture of the preferred outer voice coil assembly is performed using the following process. First, a strip of porous substrate impregnated with a curable resin is wrapped around a mandrel or tool. Second, the conductive coil is wound or placed directly on the inner or outer surface of the winding without using a conventional coil-winding adhesive coating. As described above, preferably, the lead coil has first and second coil ends that are tightly attached to the sidewalls of the winding so that they exit from selected ends of the winding. Soldered to the end of a flat ribbon-like conductor. As a result, the exterior or stiffener protects the connecting conductor of the coil from the side. Third, the exposed side of the conductive coil is covered with a stiffener or wrapped around it to form a jacket or sheath that protects the conductive coil. Next, the outer voice coil assembly is baked or cured, and the winding form, the conductive wire coil, and the stiffening body are fused to form an integral solid form. After the fusion process, a plurality of through holes are formed by punching or drilling at a plurality of positions on the side wall of the assembly selected so as to avoid the lead wire enclosed in the exterior voice coil assembly.

  The multilayer armored voice coil assembly may include an inner conductor coil and an outer conductor coil on the winding form, and another conductor coil is provided in or around the stiffener, and the exposed coil winding is used as an additional supplement. As long as each coil is enclosed either between (a) the winding and the stiffening body, or (b) between a pair of stiffening bodies, the winding-coil-stiffening-coil-stiffening body -Complete by covering, protecting and insulating with a selected number of stacks such as coils-stiffeners.

  The multilayer armored voice coil assembly may be used with a multi-voice coil driver, such as a woofer, or with a driver adapted to provide selected drive or impedance characteristics. Depending on the application, the multilayer armored voice coil may be aligned in an overlapping orientation along the axis, or after installation, a winding type is selected to change orientation to match the magnetic gap of the selected driver. It may be arranged at various positions with respect to the end. Conductor coils may have the same or different axial lengths to provide selected drive or impedance characteristics, and the conductors of the wire may be the same or different. Often, for example, the material, gauge, size, or shape may be different, and the number of windings, i.e., the number of turns, may be the same or different.

  In use, the armored voice coil assembly can withstand relatively high temperatures because the conductor is protected from damage by a stiffener or armor layer, and is also misaligned against the motor gap edge over time. And can withstand the resulting rubbing.

  The features and advantages of the present invention will become apparent upon reading the following detailed description of some preferred embodiments with reference to the accompanying drawings, in which:

  As shown in FIG. 1, a conventional voice coil 2 for use in a loudspeaker driver includes a cylindrical winding mold 4, and a coil 6 is formed by winding a plurality of wire winding portions around the winding mold. The winding form 4 supports the coil 6 in a selected orientation for suspension within the magnetic gap of the driver motor.

  2-7 show several exemplary embodiments of the armored voice coil assembly of the present invention. Beginning with the embodiment of FIG. 2, the exterior voice coil assembly 22 includes a former 24. The winding form 24 is tubular and has a continuous wall having an outer surface and an inner surface forming a hollow interior. 2-7 show a preferred cylindrical shape for the former 24. However, those skilled in the art will appreciate that the former 24 may have any cross-sectional shape. The winding mold 24 is preferably formed from a porous absorbent base material impregnated with a curable resin. Choose a variety of materials including, but not limited to, glass fabric materials, para-aramid fiber (ie Kevlar (Kevlar is a registered trademark)) material, or cotton fiber material as the porous absorbent substrate it can. The winding mold 24 is substantially impregnated with a curable resin, that is, saturated. Various curable resins can be used, including but not limited to liquid or gel polyimide resins. It will be understood that references to winding forms throughout this application relate to the winding forms described above.

  A conducting coil 26 is wound around the outer surface of the winding mold 24. The conducting wire coil 26 is surrounded by an outer stiffening body layer 28 wound around the coil. The stiffener 28 is also a porous absorbent base impregnated with a curable resin. The porous absorbent substrate is selected from the materials described above. Further, the curable resin is selected from the resins described above. In a preferred embodiment, the stiffener is a glass fabric material impregnated with a liquid or gel-like polyimide resin, ie saturated. It will be understood that references to stiffeners throughout this application relate to the stiffeners described above. This process effectively encapsulates the conductor coil 26 between the winding 24 and the stiffener 28. The outer encapsulating layer of the stiffening body 28 is also called an exterior layer. Preferably, the former 24 and the stiffening body layer 28 are coextensive and the voice coil assembly 22 in a fully sheathed state has the same cylindrical length along these common axes. The outer voice coil assembly 22 is preferably formed into a solid cylindrical shape by fusing or curing.

  3 and 4 show a second embodiment of an external voice coil assembly 32 having a winding form 34 as defined above. FIG. 4 is an enlarged detailed view of the side wall of the exterior voice coil assembly 32 shown in FIG. As explained above, the former 34 is preferably formed of a glass fabric that is substantially impregnated or saturated with polyimide resin. After the conductor coil 36 is wound around the outer surface of the former 34, it is surrounded by a stiffener 38 as described above. In the preferred embodiment, the stiffener 38 provides a single layer of polyimide resin impregnated glass fabric wrapped around the conductor coil 36 and effectively encapsulates the conductor coil 36 in the inner and outer layers of fabric and resin. After the outer voice coil assembly 32 is cured, a plurality of spaced holes or through holes 40 are drilled, preferably by drilling the outer voice coil assembly 32. In the preferred embodiment, seven through holes 40 are equally spaced around the perimeter of the exterior voice coil assembly 32. These through holes 40 provide fluid communication between the inside and the outside of the exterior voice coil assembly 32. Conductor coil 36 has first and second coil ends that are preferably soldered to flat ribbon-like conductor ends 42,44. The conductor ends 42, 44 can be tightly attached to the side wall of the mold 34 and extend from the proximal end 46 of the outer voice coil assembly 32. Thereby, the connection conductor of the coil can be protected from the side by the exterior, that is, the stiffening body 38. Advantageously, the outer voice coil assembly 32 is structurally integral and stiffened with at least two cylindrical walls 34, 36 that are substantially coaxial so that each of the cylindrical layers is thinned. Therefore, these layers are good thermal conductors when compared to conventional thick voice coil formers.

  A multilayer armored voice coil assembly 52 is shown in FIG. This assembly includes the former 54 described above. The first conductive wire coil 56 is wound around the outer surface of the winding mold 54, that is, disposed. The first conductor coil 56 is then enclosed within a first stiffening body 58 formed as described above. This process effectively encapsulates the first conductor coil 56 in the inner and outer layers made of fabric and resin. The second conductor coil 60 is wound or arranged around the outer surface of the stiffener 58 and is enclosed in the second stiffener 62. This second stiffening body 62 is preferably selected from the stiffening bodies described above. This process effectively encapsulates the second conductor coil 60 in the inner and outer layers made of fabric and resin.

  The multilayer armored voice coil assembly may be provided with an internal conductor coil as shown in FIGS. 6 and 7 or an external conductor coil as shown in FIGS. The other conducting coil is provided in or around the stiffening body layer, and the exposed conducting coil is connected between each winding coil (a) between the winding form and the stiffening body, or (b) a pair of As long as it is surrounded by any of the layers between the stiffeners, the additional stiffeners cover and protect the selected number of windings-coils-stiffeners-coils-stiffeners-coils-stiffeners, etc. Finish by insulating.

  FIG. 6 shows another embodiment of a multilayer armored voice coil assembly 72. An internal conductor coil 76 is arranged on the inner surface of the winding form 74 formed as described above. Next, the inner conductor coil 76 is enclosed in the inner stiffener 78. The inner stiffener 78 is selected from the stiffeners described above. This process effectively encapsulates the inner conductor coil 76 in inner and outer layers made of fabric and resin. The external conductor coil 80 is wound around the winding mold 74, that is, disposed. Next, the external conductor coil 80 is enclosed in the outer stiffener 82. The outer stiffening body 82 is selected from the stiffening bodies described above. This process effectively encapsulates the outer conductor coil 80 in inner and outer layers made of fabric and resin.

  FIG. 7 shows yet another multilayer armored voice coil assembly 92. This assembly includes the former 94 described above. The first internal conducting coil 96 is wound around the winding mold 94, that is, disposed. Next, the first internal conductor coil 96 is enclosed in the inner stiffener 98. This inner stiffener 98 is selected from the stiffeners described above. This process effectively encapsulates the first inner conductor coil 96 in the inner and outer layers made of fabric and resin. The second conductor coil 100 is wound, that is, disposed on the outer surface of the winding mold 94 and is enclosed in the second stiffening body 102. This second stiffening body 102 is selected from the stiffening bodies described above. This process effectively encapsulates the second conductor coil 100 in the inner and outer layers made of fabric and resin. The third conductor coil 104 is wound or arranged around the outer surface of the second stiffener 102 and is enclosed in the third stiffener 106. This third stiffener 106 is selected from the stiffeners described above. This process effectively encapsulates the third conductor coil 104 in the inner and outer layers made of fabric and resin.

  The armored voice coil assembly described above and included in the present application is formed using the following preferred manufacturing process. First, the exterior voice coil assembly winds a porous substrate impregnated with a curable resin around a mandrel or tool to form a hollow or tube-shaped winding mold having an outer surface and an inner surface. In a preferred embodiment of the invention, the porous substrate comprises a glass woven material, para-aramid fiber (ie Kevlar (Kevlar is a registered trademark)) material, or possibly a strip of carbon fiber material. Including, but not limited to. In a preferred embodiment of the present invention, the curable resin includes, but is not limited to, a polyimide resin. As shown in the accompanying drawings, the preferred shape of the mandrel or tool is substantially cylindrical. However, those skilled in the art will appreciate that other shapes may be used. Secondly, the conductor coil is wound on the winding or placed in or out of the winding when it is impregnated, i.e. wetted, using conventional coil-winding adhesive coating methods. . The conductor coil is preferably an enameled wire. In a preferred embodiment, the winding coil may be placed on the winding form or in the winding form. As noted above, preferably the first and second ends of the winding coil are snugly aligned with the winding sidewall such that they exit from a selected end (eg, proximal or free end or tip) of the winding. Soldered to a flat ribbon-like conductor end that can be attached (eg, labeled 42 and 44 in FIG. 3). Thereby, at the time of use, an exterior, ie, a stiffening body, protects the connection part of the coil conducting wire from the side. Third, the exposed side of the conductor coil is covered with a second strip of porous substrate impregnated with a curable resin or wrapped around to form a jacket or sheath that protects the coil. As noted above, porous substrates include, but are not limited to, glass fabric materials, Kevlar (Kevlar is a registered trademark) fiber material, or in some cases a carbon fiber material. The curable resin preferably includes a polyimide resin, but is not limited to this material. Next, the outer voice coil assembly is baked or cured, and the winding form, the conductive wire coil, and the stiffening body are fused to form an integral solid body. After the fusing process, a plurality of vent through holes (eg, through holes 40) are punched or drilled at a plurality of locations on the side wall of the outer voice coil assembly that is selected to avoid wires surrounded within the outer voice coil assembly. Formed by processing.

  The multilayer armored voice coil assembly may be provided with an inner conductor coil or an outer conductor coil in the winding form, and the other conductor coil is provided in or around the stiffening body layer, and the exposed conductor coil As long as each wire coil is enclosed either either (a) between the winding and the stiffener, or (b) between a pair of stiffener layers, the additional stiffener will allow the selected number of winding-coils. -Finishing is performed by covering, protecting, and insulating by laminating a stiffening body, a coil, a stiffening body, a coil, and a stiffening body.

  The multilayer armored voice coil assembly may be used, for example, with a multi-voice coil driver, such as a woofer, or with a driver adapted to provide selected drive characteristics or impedance. Depending on the application, the layered conductor coil may be aligned in an overlapping orientation along the axis, or, after installation, selected for the winding form to change orientation to match the magnetic gap of the selected driver. You may arrange | position in various positions regarding an edge part. Conductor coils or voice coils can also have the same or different axial lengths to provide selected drive or impedance characteristics, such as wire conductors (eg, material, gauge / size Or the shape) may be the same or different, or the winding or the number of windings may be the same or different.

  In use, the armored voice coil assembly can withstand high operating temperatures and can withstand misalignment over time and thereby friction against the motor gap edges. This is because the coil conductor is protected from damage by an exterior or stiffening body made of a porous substrate impregnated with a curable resin.

  Referring to FIG. 8, a loudspeaker driver 200 incorporating the exterior voice coil of the present invention is shown. The driver optionally includes a representative circular basket 202 that supports a frustoconical driver diaphragm 204. Normally, the small end 206 of the diaphragm 204 supports the substantially cylindrical outer voice coil former 22. A wound conductive voice coil 26 with a positive end terminal and a negative end terminal is placed in the former 22. The driver optionally uses a basket 202 that closely matches the frustoconical shape of the driver diaphragm. The basket 202 supports the motor magnet 208 and the circular diaphragm surround or spider 210 in alignment with the magnetic pole piece 212 in the axial direction, and can move the diaphragm in the axial direction in response to excitation of the exterior voice coil 22. it can. The loudspeaker driver 200 preferably includes one or more magnetic structures. These magnetic structures include one or more permanent magnets (eg, 208) for providing magnetic flux. The magnetic flux is concentrated across the magnetic gap 214 where the magnetic flux acts on the outer voice coil 22.

  A common concern with such loudspeakers is the problem of driver damage due to thermal overload. For many applications, a large amount of power is required to provide an appropriate sound pressure level, so generating a loud sound output from a loudspeaker requires passing a very large current through the voice coil conductor 26. This current generates heat in the voice coil, and this heat is dissipated through the former 24 and the stiffener 28 to the adjacent air space and metal structure. The heat flowing through the mold 24 is partially dissipated through the driver pole piece 212 and the heat flowing through the stiffener 28 is through an external magnetic gap that forms part of the driver pot or surface. Is released.

  Any of the outer voice coils described in the above exemplary embodiments can be used by the driver 200 to provide high output handling characteristics and to greatly increase the range of acceptable input drive signals. One or more drivers, including armored voice coils, can be incorporated into the loudspeaker system. By way of example, a loudspeaker system that includes a woofer with one or more driven voice coils has a multi-layer armored voice coil 92, and a midrange driver and one or more tweeters can be a basic armored voice coil. 22.

  It will be apparent to those skilled in the art that the voice coil former of the present invention can be formed in a variety of configurations without departing from the scope of the present invention. As used herein, the term “tubular” is not limited to a cylindrical shape or a circular cross-sectional form, but refers to a form or bobbin-like structure having an outer wall that forms a lumen or volume. A tube winding of square, hexagonal, or optional shape (eg, kidney shape) can be an outer voice coil according to the present invention. For example, if the cross-section of a loudspeaker pole piece is similar to a rhombus with five sides, the exterior voice coil for the application has a hollow interior sized to receive the pole piece. Similar to a tightly fitted tube with five sides.

  While preferred embodiments of the new and improved method have been described, it will be appreciated by those skilled in the art that other variations and modifications may be made in light of the teachings herein. Accordingly, it should be understood that all such variations and modifications are considered to be included within the scope of this specification.

FIG. 1 is a partial cross-sectional front view of a conventional voice coil wound around a conventional cylindrical voice coil winding mold. FIG. 2 is a partial cross-sectional front view of an exterior voice coil assembly having a cylindrical winding form and an exterior outer cover or stiffening body according to the present invention. FIG. 3 is a front view of a second embodiment of the exterior voice coil assembly according to the present invention. 4 is a partial cross-sectional enlarged detailed front view of the exterior voice coil assembly of FIG. 3 according to the present invention. FIG. 5 is a partial cross-sectional front view of a multilayer outer voice coil assembly according to the present invention. FIG. 6 is a partial cross-sectional front view of another multilayer armored voice coil assembly according to the present invention. FIG. 7 is a partial cross-sectional front view of another multilayer armored voice coil assembly according to the present invention. FIG. 8 is a partial cross-sectional front view of a loudspeaker driver including an exterior voice coil assembly according to the present invention.

Explanation of symbols

22 Exterior voice coil assembly 24 Winding type 26 Conductor coil 28 External stiffening layer

Claims (11)

In the exterior voice coil assembly,
A tubular form having an outer surface and an inner surface, formed of a porous absorbent substrate impregnated with a curable resin;
A first conductor coil applied to the outer surface or the inner surface of the tubular winding mold;
A first stiffening body including a porous absorbent base material impregnated with a curable resin applied to the first conductive coil ;
A second conductor coil applied to the first stiffener;
A second stiffening body including a porous absorbent base material impregnated with a curable resin applied to the second conductive wire coil ,
The tube-shaped winding mold, the first conductive coil, and the first stiffening body are fused together, and the first conductive coil is enclosed in an envelope formed by the tubular winding mold and the first stiffening body. The substance of
The first stiffener, the second conductor coil, and the second stiffener are fused together, and the second conductor coil is enclosed in a second envelope formed by the first stiffener and the second stiffener. An external voice coil assembly that makes a solid body . In the exterior voice coil assembly,
A tubular form having an outer surface and an inner surface, formed of a porous absorbent substrate impregnated with a curable resin;
A first conductor coil applied to the outer surface or the inner surface of the tubular winding mold;
A first stiffening body including a porous absorbent base material impregnated with a curable resin applied to the first conductive coil;
A second conducting coil applied to the inner surface of the tubular winding mold;
A second stiffening body including a porous absorbent base material impregnated with a curable resin applied to the second conductive wire coil,
The first conductor coil is applied to the outer surface of the tubular winding mold ,
The tube-shaped winding mold, the first conductive coil, and the first stiffening body are fused together, and the first conductive coil is enclosed in an envelope formed by the tubular winding mold and the first stiffening body. The substance of
The winding mold, the second conducting coil, and the second stiffening body are fused together, and the second conducting coil is enclosed in a second envelope formed by the winding mold and the second stiffening body. An external voice coil assembly that makes it a reality. The exterior voice coil assembly according to claim 1 or 2 ,
The outer voice coil assembly is selected from the group consisting of a glass fabric material, a para-aramid fiber material, and a carbon fiber material. The exterior voice coil assembly according to claim 1 or 2 ,
The curable resin is an exterior voice coil assembly, which is a polyimide resin. In a method for manufacturing an exterior voice coil assembly,
a) providing a tubular form comprising a porous absorbent substrate impregnated with a curable resin having an outer surface and an inner surface;
b) positioning the first conductive coil on the outer surface or the inner surface of the tubular winding mold;
c) applying a first stiffening body comprising a porous absorbent substrate impregnated with a curable resin to the first conducting coil;
d) The tubular winding mold, the first conducting coil, and the first stiffening body are fused together, and the first conducting coil is enclosed within an envelope formed by the tubular winding mold and the first stiffening body. The process of making a solid entity ,
e) providing a second conductor coil applied to the first stiffener;
f) applying a second stiffening body comprising a porous absorbent substrate impregnated with a curable resin to the second conducting coil;
g) The first stiffener, the second conductor coil, and the second stiffener are fused together, and the second conductor coil is enclosed within an envelope formed by the first stiffener and the second stiffener. And integrating into a solid body . In a method for manufacturing an exterior voice coil assembly,
a) providing a tubular form comprising a porous absorbent substrate impregnated with a curable resin having an outer surface and an inner surface;
b) positioning the first conductive coil on the outer surface or the inner surface of the tubular winding mold;
c) applying a first stiffening body comprising a porous absorbent substrate impregnated with a curable resin to the first conducting coil;
d) The tubular winding mold, the first conducting coil, and the first stiffening body are fused together, and the first conducting coil is enclosed within an envelope formed by the tubular winding mold and the first stiffening body. The process of making a solid entity,
e) providing a second conducting coil applied to the inner surface of the tubular winding;
f) applying a second stiffening body comprising a porous absorbent substrate impregnated with a curable resin to the second conducting coil;
g) The tube-shaped winding mold, the second conductive coil, and the second stiffening body are fused together, and the second conductive coil is enclosed in an envelope formed by the winding mold and the second stiffening body. The process of making
The method wherein the first conductor coil is positioned on an outer surface of the tubular form. The method according to claim 5 or 6,
Before passing from Kigaimen to said inner surface further comprises as engineering of forming a vent through holes for these fluid communication with, the method. The method according to claim 5 or 6 , wherein
Providing the tubular form includes providing a tubular form comprising a porous absorbent substrate selected from the group consisting of a glass fabric material, a para-aramid fiber material, and a carbon fiber material; Method. The method according to claim 5 or 6 , wherein
The method of providing a tubular form includes providing a tubular form comprising a porous absorbent substrate impregnated with a curable polyimide resin. The method according to claim 5 or 6 , further comprising:
Soldering flat ribbon-like conductor ends to the first and second ends of the first conductor coil;
Covering the conductor end with the second stiffener. A loudspeaker including the exterior voice coil assembly according to any one of claims 1 to 4 .

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